1. Field of the Invention
This invention relates to a multi-positional bed. Such beds are used in hospitals, and are also used in domestic situations and in homes for the elderly and infirm, where it is necessary to have a bed which can be adjusted to suit a particular individual or which can successively occupy a number of different positions, for example in order to reduce the risk of bed sores.
2. Description of the Related Art
In such beds the mattress rests on a supporting surface which normally consists of three or four sections pivotally connected to one another. In the case of a four-section supporting surface these are, starting from the head end of the bed, a back section, a buttocks section, a thigh section and a calf section. In the case of a three-section supporting surface the thigh and calf sections are replaced by a single section, or the buttocks section is omitted. The sections are connected to one another in such a way as to allow pivotal movement between adjacent sections about parallel axes transverse to the length of the bed. Such beds also normally have provision for the whole supporting surface to be moved vertically between high and low positions. The user normally gets into the bed with the supporting section in its low position (this is particularly convenient when the user is in a wheelchair), and the supporting surface can thereafter be raised so as to make it easier for those attending the user.
Some beds also allow the whole supporting surface to be tilted about the transverse and/or longitudinal axis of the bed. However, when these additional movements are incorporated the resultant mechanism tends to be highly complex and therefore very expensive. It is an object of the present invention to provide a bed in which all the types of adjustment referred to above are present, but which does not require a mechanism of great complexity.